Submission #136428

# Submission time Handle Problem Language Result Execution time Memory
136428 2019-07-25T09:47:02 Z onjo0127 Link (CEOI06_link) C++11
92 / 100
597 ms 58456 KB
#include <bits/stdc++.h>
using namespace std;
#define sz(V) ((int)V.size())

const int _N = 500001, DBG = 0;
bool chk[_N];
int N, K, A[_N], vs[_N], dep[_N], rt[_N], rid[_N], ith[_N], p[11][_N], cs[11][_N], ans;
vector<vector<int> > R;
vector<int> S, G[_N];

void go(int x, int col) {
	S.push_back(x);
	vs[x] = col;
	if(vs[A[x]]) {
		if(vs[A[x]] == col) {
			vector<int> T;
			while(1) {
				int tmp = S.back(); S.pop_back();
				T.push_back(tmp);
				if(tmp == A[x]) break;
			}
			reverse(T.begin(), T.end());
			for(int i=0; i<T.size(); i++) rid[T[i]] = sz(R), ith[T[i]] = i+1;
			R.push_back(T);
		}
	}
	else go(A[x], col);
}

int mrk(int x, int k) {
	if(k <= 0) return x;
	chk[x] = 1;
	int d;
	if(ith[x]) {
		if(ith[x] < ith[A[x]]) d = ith[A[x]] - ith[x];
		else d = ith[A[x]] - ith[x] + sz(R[rid[x]]);
	}
	else if(ith[A[x]]) return A[x] = mrk(rt[x], k - dep[x]);
	else d = dep[x] - dep[A[x]];
	return A[x] = mrk(A[x], k - d);
}

void dfs(int RT, int x, int d) {
	// printf("dfs: x: %d, d: %d\n", x, d);
	dep[x] = d; rt[x] = RT;
	for(auto& it: G[x]) dfs(RT, it, d+1);
}

void showstat() {
	puts("Showing...");
	printf("answer: %d\n", ans);
	for(int i=1; i<=N; i++) printf("%d", chk[i]);
	puts("\n---------------------");
}

int main() {
	vector<int> Q;
	scanf("%d%d",&N,&K);
	for(int i=1; i<=N; i++) {
		int a, b; scanf("%d%d",&a,&b);
		A[a] = b;
	}
	for(int i=1; i<=N; i++) if(!vs[i]) go(i, i);
	for(int i=1; i<=N; i++) if(!ith[i]) {
		G[A[i]].push_back(i);
		Q.push_back(i);
	}
	for(int i=1; i<=N; i++) if(ith[i]) dfs(i, i, 0);
	chk[1] = 1;
	mrk(A[1], K);
	if(DBG) showstat();
	sort(Q.begin(), Q.end(), [&](int PP, int QQ) { return dep[PP] > dep[QQ]; });
	for(auto& it: Q) {
		if(chk[it]) continue;
		mrk(it, K); ++ans;
	}
	if(DBG) showstat();

	set<int> st;
	for(auto& it: R) {
		st.clear();
		int M = sz(it);
		for(int j=0; j<M; j++) {
			p[0][j] = j; cs[0][j] = 0;
			if(!chk[it[j]]) st.insert(j);
		}
		if(st.empty()) continue;

		for(auto& jt: st) {
			if(jt <= M-K) {
				auto kt = st.lower_bound(jt + K);
				if(kt == st.end()) {
					p[0][jt] = *st.begin();
					cs[0][jt] = *st.begin() - jt + M;
				}
				else {
					p[0][jt] = *kt;
					cs[0][jt] = *kt - jt;
				}
			}
			else {
				auto kt = st.lower_bound(jt + K - M);
				if(kt == st.end()) p[0][jt] = jt, cs[0][jt] = M;
				else p[0][jt] = *kt, cs[0][jt] = *kt - jt + M;
			}
			// printf("next[%d]: %d, cost: %d\n", jt, p[0][jt], cs[0][jt]);
		}

		int L;
		for(int i=1; (1<<i)<=M; i++) {
			for(int j=0; j<M; j++) {
				p[i][j] = p[i-1][p[i-1][j]];
				cs[i][j] = cs[i-1][j] + cs[i-1][p[i-1][j]];
				cs[i][j] = min(cs[i][j], M);
			}
			L = i;
		}
		int mn = 1e9;
		for(auto& jt: st) {
			int sum = 0, now = jt, cnt = 0;
			for(int j=L; j>=0; j--) if(sum + cs[j][now] < M) {
				sum += cs[j][now], cnt += (1<<j), now = p[j][now];
				// printf("now: %d, sum: %d, cnt: %d\n", now, sum, cnt);
			}
			mn = min(mn, cnt + 1);
			// printf("jt: %d, cnt: %d\n", jt, cnt + 1);
		}
		ans += mn;
	}
	printf("%d", ans);
	return 0;
}

Compilation message

link.cpp: In function 'void go(int, int)':
link.cpp:23:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i=0; i<T.size(); i++) rid[T[i]] = sz(R), ith[T[i]] = i+1;
                 ~^~~~~~~~~
link.cpp: In function 'int main()':
link.cpp:58:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&N,&K);
  ~~~~~^~~~~~~~~~~~~~
link.cpp:60:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   int a, b; scanf("%d%d",&a,&b);
             ~~~~~^~~~~~~~~~~~~~
link.cpp:122:43: warning: 'L' may be used uninitialized in this function [-Wmaybe-uninitialized]
     sum += cs[j][now], cnt += (1<<j), now = p[j][now];
                                       ~~~~^~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 13 ms 12152 KB Output is correct
2 Correct 13 ms 12280 KB Output is correct
3 Correct 13 ms 12280 KB Output is correct
4 Correct 16 ms 12408 KB Output is correct
5 Correct 18 ms 12536 KB Output is correct
6 Correct 34 ms 14840 KB Output is correct
7 Correct 49 ms 15860 KB Output is correct
8 Correct 67 ms 18104 KB Output is correct
9 Correct 89 ms 23896 KB Output is correct
10 Correct 86 ms 22900 KB Output is correct
11 Incorrect 161 ms 47192 KB Output isn't correct
12 Correct 173 ms 23860 KB Output is correct
13 Correct 237 ms 35924 KB Output is correct
14 Correct 286 ms 40236 KB Output is correct
15 Correct 343 ms 45360 KB Output is correct
16 Correct 408 ms 56244 KB Output is correct
17 Correct 448 ms 50120 KB Output is correct
18 Incorrect 530 ms 50108 KB Output isn't correct
19 Correct 513 ms 50608 KB Output is correct
20 Correct 478 ms 48464 KB Output is correct
21 Correct 523 ms 53636 KB Output is correct
22 Correct 533 ms 55576 KB Output is correct
23 Correct 597 ms 58456 KB Output is correct
24 Correct 558 ms 55740 KB Output is correct
25 Correct 572 ms 54632 KB Output is correct